In a current wireless communications system, to ensure mobility of a user equipment (UE) and provide higher bandwidth for the UE, the UE may access a plurality of base stations simultaneously, so that the plurality of base stations can serve the UE simultaneously. In this case, data transmission between the UE and the plurality of base stations is a focus in the industry.
That the UE simultaneously accesses two base stations is used as an example. Based on roles of the two base stations, the two base stations are referred to as a primary base station and a secondary base station. When the UE transmits data to the primary base station, the UE may directly transmit the data to the primary base station, or may first transmit the data to the secondary base station, and the secondary base station forwards the data to the primary base station. Likewise, when the primary base station transmits data to the UE, the primary base station may directly transmit the data to the UE, or may first transmit the data to the secondary base station, and the secondary base station forwards the data to the UE. When the data transmission fails, retransmission is performed based on the foregoing process.
In a process of implementing the present disclosure, the prior art has the following disadvantages:
When the data transmission fails due to a relatively poor condition of a radio channel between the UE and the primary base station or a relatively poor condition of a radio channel between the UE and the secondary base station, a plurality of retransmissions may be needed for successful transmission. The plurality of retransmissions may cause a high network latency of data transmission.